A general gas turbine includes a compressor, a combustor, and a turbine. The compressor obtains high-temperature/high-pressure compressed air by compressing air received from an air inlet. The combustor obtains a high-temperature/high-pressure combustion gas by supplying a fuel to the compressed air and burning the fuel. The turbine is driven by the combustion gas so that a generator coaxially connected thereto is driven.
The turbine of the gas turbine has a configuration in which a plurality of vanes and a plurality of blades are alternately disposed inside a casing in the combustion gas flow direction. When a combustion gas generated by the combustor passes through the plurality of vanes and the plurality of blades, a rotor is rotationally driven and the generator connected to the rotor is driven.
Incidentally, a part of the compressed air obtained in the compressor of the gas turbine is bled and is used to cool the vanes of the turbine. Further, a part of the compressed air is guided to the outside, is cooled by an air cooler, and is used to cool the turbine disks and the blades. Furthermore, a part of the air having been used to cool the vanes of the turbine flows outward from a blade surface or a blade trailing edge, while another part of the air flows into a disk cavity provided with a labyrinth seal between the turbine disks at the front and rear stages so as to cool the seal portion and the blade roots.
An example of the gas turbine is disclosed in, for example, Patent Literature 1.